Multiple stage pumping unit



Aug- 11 1964 N. w. GALLAWAY ETAI. 3,143,968

MULTIPLE STAGE PUMPING UNIT 2 Sheets-Sheet l Filed Oct. 25, 1963 m AWHTW Aom LL LD AR GAWH M w wm /Y R M B Nw A TTORNE Y Allg' 11, 1964 N. Kw. GALLAWAY ETAL 3,143,968

MULTIPLE STAGE PUMPING UNIT Filed Oct. 25, 1963 2 Sheets-Sheet 2 NORR/S W. GALLA WA Y JOHN EDWARD LOTT INVENTORS www ATTORNEY United States Patent O "ce 3,143,968 MULTIPLE STAGE PUMPWG UNIT Norris W. Gallaway and John Edward Lott, Fort Worth, Tex., assiguors to American Manufacturing Company of Texas, Fort Worth, Tex., a corporation of Texas Filed Oct. 25, 1963, Ser. No. 313,957 Claims. (Cl. 10S- 5) This invention relates to pumping wells and has reference to apparatus whereby liquid from an earth formation is raised in stages so as to reduce the strain on a string of sucker rods.

Heretofore, many deep oil wells were produced by gas lift so long as they had suflicient pressure. If, after the well ceased to llow, and if the well was not too deep, pumping equipment was installed and the well was again produced. However, many deep wells were abandoned after the pressure dropped, even though there were large amounts of oil remaining in the earth formations, because the necessary lengths of the sucker rod strings were so great that they could not support their own weight and the weight of the column of oil extending to the earths surface.

Stage lifting has been proposed for use in water Wells, which are comparatively shallow, but such prior devices were not suitable for oil wells. Such prior devices made no provision for accumulated oil and/or gas in the well casing and no provision for lubricating that length of sucker rod string above the first stage. In vertually all deep pumping wells there is contact and rubbing of the rods against the inner walls of the tubing.

The present invention will find some use in relatively shallow oil wells because it makes possible the use of lighter rods, smaller power sources and smaller gear boxes.

An object of the invention is to provide equipment for pumping wells from depths below present single string sucker rod capacities.

A particular object is to provide means reducing sucker rod stress and rod failure in deep wells.

Another object is to provide means dividing the weight of fluid lifted, thereby making smaller surface equipment possible.

Another object is to provide means lubricating that length of sucker rod above the irst stage.

A further object is to provide means to accommodate accumulated gas within the well casing and to prevent the accumulation of an excessive amount of oil in the casing above the lirst stage.

These and other objects of the invention will become apparent from the following description and the accompanying drawings, in which:

FIGURE 1 is a schematic elevational and sectional View of a well and showing multiple stage lift equipment installed therein in accordance with the invention. FIG- URE 1, as well as other iigures herein shown, is considerably out of proportion, it being understood that the well may be, for example, 10,000 feet deep or deeper.

FIGURE 2 is an enlarged vertical schematic sectional view of a first form of the invention.

FIGURE 3 is a View similar to FIGURE 2 but showing another form of the invention, and

FIGURES 4 and 5 are also vertical sectional Views showing additional forms of the invention.

In FIGURE 1 there is shown a multiple pumping unit 10 such as illustrated and described in U.S. Patent No. 2,997,887, dated August 29, 1961, wherein there is a primary pumping unit 11 connected with a secondary pumping unit 12 by a generally horizontal rigid link 13. One end of the link 13 is connected with the wrist pin 14 of the crank 15 of the primary unit 11, whereas the re- 3,143,938! Patented Aug. 11., 1964 maining end of the link is connected with a rocker arm 16 depending from the walking beam 17 of the secondary unit 12. As in conventional practice, a pitman 18 connects the wrist pin 14 with the walking beam 19 of the primary unit 11. Both units 11 and 12 have horse heads 20 and 21 on the adjacent ends of their walking beams 19 and 17, and bridles 22 and 23 thereon for engagement with the upper ends of sucker rod strings 24 and 25. The primary unit 11 operates the secondary unit 12 through the link 13 and, by reason of the described link arrangement, the secondary unit is aproximately degrees out of phase with the primary unit. Thus, the peak torque loads of the two units are out of phase with each other and neither, in the present invention, lifts the total weight of oil extending from the production zone to the earths surface. Although the multiple pumping unit of the referred to patent is preferred in the operation of the present invention, separate single independent pumping units may be employed.

The well illustrated in FIGURE 1 includes a casing 26 which extends to a production zone, not shown, beneath the earths surface. A well head 27 on the upper end of the casing 26 supports two strings of tubing 28 and 29 in which the sucker rod strings 24 and 25 operate. Certain polished lengths of the sucker rod strings 24 and 25 are slidable in stuffing boxes 30 and 31 on the upper ends of the tubing strings which project above the well head 27. The lirst or primary tubing string 28 extends down the casing 26 to near the bottom thereof where it is connected with a pump 32 which has a strainer nipple 33 on its lower end. Approximately one-third the way up the casing 26 there is a casing packer 34 through which the first tubing string 28 passes.

A feature of the invention is directed to means allowing Vgas from the producing formation to pass upwardly through the packer 34 to the well head where it is released by conventional means, not shown, to reduce gas pressure within the casing 26. Similarly, means are provided for returning excess oil accumulated above the packer 34 to the bottom of the well. For both purposes there is an open relief tube 35 through the packer 34 and which tube extends a distance above the packer to provide a reservoir 36 in the casing 26 from which oil is pumped to the earths surface.

In the drawings, a length of the first tubing string 28, and comprising a part of the pump 32, is designated as a working barrel 37 in which there is a plunger 38. The pump 32 is conventional and in addition to the working barrel 37 and the plunger 38, which is connected with the lower end of the sucker rod string 24, there is a standing valve 39 in the lower end of the working barrel 37 and a traveling valve 40 in the plunger, all in the usual manner.

A length of the iirst tubing string 24 in all forms of the invention is perforated, at 41, above the packer 34 and within the area of the casing 26 designated as the reservoir 36. In the first form of the invention, FIG- URE 2, there is a stuffing box 42 within the tubing string 28 and slidably receives the sucker rod string 24. The stufng box 42 is located above the perforations 41 and approximately opposite the upper end of the relief tube 35. A bleeder port 43 may be provided in the tubing string 28, preferably below the top of the relief tube 35 but above the stuiing box 42.

The second tubing string 29 extends downwardly into the reservoir 36 in all forms of the invention and the lower end has a strainer nipple 44 to admit oil to a pump, generally designated by the numeral 45. Like the irst described pump 32, a lower portion of the second tubing string 29 is designated as a working barrel 46 which has a standing valve 47 in the lower end thereof, a plunger 48 connected with the lower end of the second sucker rod string 25, and a traveling valve 48 in the plunger. Connected with the upper end of the second tubing string 29, and above the well head 27, there is a flow line 50. Also above the well head 27 there is a short pipe 51 connecting the upper end of the second tubing string 29 with the irst tubing string 28. As will become apparent, the short length of pipe 51 has to do with lubricating the first tubing string 24 above the down-hole stuffing box 42.

The form of the invention illustrated in FIGURE 3 is identical with the form illustrated in FIGURE 2, except the down hole stufng box 42 and port 43 thereabove are eliminated, and a nozzle orifice 52 is added to the short length of pipe 51, and which orifice is directed to the first sucker rod string 24 for lubricating the same.

The form of the invention illustrated in FIGURE 4 is identical with those of either FIGURE 2 or 3, except the down hole stuffing box 42, port 43 and relief tube 35 are eliminated, and instead there is an arrangement of oppositely disposed spring loaded poppet valves 53 and 54 in the packer 34. A metal body 55 is provided in the packer 34 to receive and mount the poppet valves 53 and 54, which valves are of conventional design. Itis to be noted that the first valve 53 is arranged to open if the column of oil in the casing 26 above the packer 34 becomes excessive, yand that the arrangement of the second valve 54 is such that it will open if there is excessive gas pressure below the packer.

The form of the invention illustrated in FIGURE 5 is like FIGURE 4, but is designed to accommodate large volumes of gas and at the same time prevent co-mingling of gas in the oil above the packer 34. To this end the poppet valve 54 is eliminated and in its stead there is a vent tube 56 extending through the packer body 55 and upwardly above the reservoir area 36.

The operation of the first described form of the invention is as follows: 4

The sucker rod strings 24 and 25 are cyclically reciprocated by the pumping units 11 and 12 and thus operate the pumps 32 and 45. Oil is raised through the lower portion of the first tubing string 28 from the bottom of the well and enters the reservoir 36 through the ports 41, and from the reservoir is raised upwardly through the second tubing string 29 and out through the flow line 50. An amount of oil enters the upper portion of the first tubing string 28 above the stufling box 42 by way of the connecting short pipe 51. The oil above the stuffing box 42 lubricates the length of sucker rod string 24 Y thereabove. Since salt water is usually present with the oil, it is preferred that the liquid above the s tufiing box is circulated. This is accomplished by the port 43 in the tubing string 28 and the liquid passing therethrough enters the reservoir 36. Excess liquid, oil or salt water, overflows through the relief tube 35 and falls to the bottom of the well. Similarly, excess liquid pumped from the well enters the reservoir 36 and overows through the relief tube 35.

The second form of the invention operates in substantially the same manner except the level of the oil in the first tubing string 28 is approximately level with the top of the relief tube 3S, but which level varies during the pumping operation. The length of sucker rod string 24 thereabove is lubricated by liquid from the nozzle orifice 52.

The operation of the form of the invention illustrated in FIGURE 4 has been referred to in the foregoing, but it is pointed out that the strength of the spring action of the first poppet valve 53 determines the height of the oil in the casing 26 above the packer 34. The pumping 4.- action is in accordance with that described in connection with FIGURES 2 and 3.

The operation of the form of the invention illustrated in FIGURE 5 is like that described in connection with FIGURE 4 except gas from below the packer 34 is conducted through the oil above the packer 34 without comingling therewith.

The invention is not limited to the exemplary constructions herein shown and described, but may be made in various ways within the scope of the appended claims.

What is claimed is:

1. Multiple stage pumping apparatus comprising: first and second tubing strings in a Well, said first tubing string extending from the earths surface to the bottom of the well and said second tubing string extending downwardly in the well to a distance substantially above the bottom of the well, reciprocating pumps on the lower ends of said tubing strings, a well packer around said first tubing string below the lower end of said second tubing string and the pump thereon, sucker rod strings within said tubing strings and operatively connected with said pumps, means reciprocating said sucker strings, at least one opening in said first tubing string above said packer, means providing a reservoir in the well above said packer and receiving the lower end of the pump on said second tubing string therein, and means extending through said packer communicating the upper and lower portions of said well.

2. Multiple stage pumping apparatus as defined in claim 1, and wherein said means reciprocating said sucker rod strings include longitudinally aligned separate walking beam pumping units on the earths surface and wherein one of said pumping units includes a pitman crank and the other said pumping unit includes a depending rocker arm, and a rigidlink pivotally connected at its ends with said pitman crank and said rocker arm.

3. Multiple stage pumping apparatus as dened in claim 1 and wherein said Ameans providing a reservoir in the well above said packer is comprised of a relief tube extending through said packer and upwardly therefrom a distance determining the top of the reservoir.

4. Multiple stage pumping apparatus as defined in claim 1, and including means lubricating said sucker rod therein. K 5. Multiple stage pumping apparatus as defined in claim 4, and wherein said means lubricating said sucker rod string iscomprised of a down hole stuffing box in said first tubing string above said opening therein, and communication means between said tubing strings at the upper ends thereof.

6. The construction defined in claim 5 and including a bleeder port in said first tubing string above said stuffing box.

7. Multiple stage pumping apparatus as defined in claim 4, and wherein said means lubricating said sucker rod string is comprised of a pipe connecting the upper ends of said tubing strings and a nozzle in said pipe directed toward said sucker rod string.

8. Multiple stage pumping apparatus as defined in claim 1, and wherein means providing a reservoir in said well is comprised of a spring loaded downwardly directed poppet valve in said packer.

9. The construction defined in claim 8 and including an upwardly directed spring loaded poppet Valve in said packer.

l0. The construction defined in claim 8, and including a vent pipe extending through said packer and upwardly above said reservoir.

No references cited. 

1. MULTIPLE STAGE PUMPING APPARATUS COMPRISING: FIRST AND SECOND TUBING STRINGS IN A WELL, SAID FIRST TUBING STRING EXTENDING FROM THE EARTH''S SURFACE TO THE BOTTOM OF THE WELL AND SAID SECOND TUBING STRING EXTENDING DOWNWARDLY IN THE WELL TO A DISTANCE SUBSTANTIALLY ABOVE THE BOTTOM OF THE WELL, RECIPROCATING PUMPS ON THE LOWER ENDS OF SAID TUBING STRINGS, A WELL PACKER AROUND SAID FIRST TUBING STRING BELOW THE LOWER END OF SAID SECOND TUBING STRING AND THE PUMP THEREON, SUCKER ROD STRINGS WITHIN SAID TUBING STRINGS AND OPERATIVELY CONNECTED WITH SAID PUMPS, MEANS RECIPROCATING SAID SUCKER STRINGS, AT LEAST ONE OPENING IN SAID FIRST TUBING STRING ABOVE SAID PACKER, MEANS PROVIDING A RESERVOIR IN THE WELL ABOVE SAID PACKER AND RECEIVING THE LOWER END OF THE PUMP ON SAID SECOND TUBING STRING THEREIN, AND MEANS EXTENDING THROUGH SAID PACKER COMMUNICATING THE UPPER AND LOWER PORTIONS OF SAID WELL. 